The
Jupiter Intermediate Range Ballistic Missile (IRBM) is the least
known and shortest lived of the early U.S. nuclear missiles. In
spite of this, it made major contributions to the development of
U.S. rocketry.

After developing the
Redstone Medium Range Ballistic Missile (MRBM) in 1954 the
Army's missile research group at Redstone Arsenal began initial
studies into a more powerful missile. This improved weapon was to be
capable of delivering a nuclear payload a distance of 1,000 miles.
Early the next year, on 14 February 1955, the United States Science
Advisory Committee issued the Killian Report, that urged the
development of an IRBM concurrently with the ICBM. This report, plus
the Soviet Union's own testing of IRBM's, prompted Secretary of
Defense

Charles Wilson on 8 November 1955
to approve development of the
Thor IRBM. The same day he also ordered the Jupiter development
with a sea launch capability. Initially, the collaboration with the
Navy was beneficial to the Jupiter program. To meet the Navy's
deployment requirements, the planned length of the Jupiter was
reduced and, instead of control fins, a gimbaled rocket engine was
incorporated. Regardless of this initial progress, however, the
Jupiter's liquid fuel engine system was completely unsuitable for
the Navy's needs. Since engine tests had been underway since
November of 1955, the Army was not willing to change to a solid fuel
engine. As a result of this impasse, on 16 February 1956 the Navy
began development of its own version of the Jupiter using solid
fuel. The Navy called their system Jupiter S.

On 28 November 1956, Secretary of
Defense issued a "Roles and Missions" directive that gave the U.S.
Air Force sole control of all missiles with a range greater than 200
miles. The instant the directive was issued the Jupiter became an
Air Force weapon. All requirements work, however, was still to be
done at the Army's Redstone Arsenal. Thus, when the first missile
was launched from Cape Canaveral in March 1957 it was an Army team
that operated it. Though the launch was unsuccessful, on 31 May a
successful flight of 1,500 miles was achieved. Since this was four
months before the first successful
Thor flight, the Jupiter became the first successful U.S. IRBM.

On 27 November 1957, the Secretary of Defense, Neil McElroy, announced that both the
Thor and Jupiter would be deployed. In 1958, the U.S. Air Force
activated the 864th and 865th Strategic Missile Squadrons at the Redstone Arsenal in
Huntsville, Alabama where the Jupiter was being developed.

The final virtue of the Jupiter
was its
ablative re-entry vehicle. Unlike the Thor's blunt Mk-11 RV,
this RV penetrated the atmosphere at a higher speed. This made it
tougher to intercept, and made it less susceptible to upper level
wind drift, thus it was significantly more accurate. These two facts
alone prompted the Air Force to abandon the Mk-11 and use ablative
RVs on all future ICBMs.

The Jupiter was on display in the museum rocket garden until 2009 when it was removed for
restoration.